The present invention pertains to a compensator coupling having flanges connected by means of a plurality of bolts, one of said flanges being joined to a rotating drive member and the other to a rotating driven member, wherein the bolts consist of a journal fastened to one of the two flanges and a sleeve fastened to the other flange. The sleeve is supported on the journal by means of an axially convex surface formed by a spherical shaped ring which is forced against the sleeve and is displaceable with respect to the journal.
Compensating couplings of this type have been known for a long period of time and are used to transmit rotating movements even in the case of axles which are not aligned with each other but include a slight angle between them. In practice, this occurs frequently in the case of long shafts which are sagging to some extent, so that the ends of the shafts form an angle with each other. This is found usually in instances wherein drives are coupled with each other and in the case of long roll drives which experience a certain sagging. Under these conditions a certain alignment and bending error is always obtained even with the most careful installation, and this error acts in the form of edge loads on the corresponding bearing locations, thereby leading to the premature wear of these elements. To compensate for this known error, a number of different couplings are used to transmit rotating motion while acting as compensating couplings. Attempts had been made earlier to effect the transmission of rotating motions by means of compensating couplings of the afore-described type in such a way that the bearing support between the journal and the sleeve was provided with a certain clearance through the spherical ring, thereby allowing for an oblique position of the axles with respect to each other (See U.S. Pat. No. 981,736; German Offenlegungsschrift No. 714,243 and German Pat. No. 1,909,213). In U.S. Pat. No. 981,736 this clearance is necessary, because the spherical rings are displaced in translatory fashion on the journal and are thus displaceable with respect to each other in parallel only. However, in the transition from the aligned position of the axles into an angled position, the spherical rings must move on a circular path in relation to each other. These essentially contradictory movements may be effected for small rotating angle errors only by means of a bearing clearance. In U.S. Pat. No. 981,736 the clearance is apparently provided between the journal and the spherical ring, as the sleeve tightly encloses the spherical ring.
The clearance existing between the journal and the sleeve leads to a phase shift in the transmission of the rotating motion from the drive member to the driven member. Furthermore, there is a knock in the coupling which has a particularly strong effect in reversing motion. A genuine, rotationally rigid transmission is therefore not possible with the known compensating couplings. Technically, this configuration is suitable only for low numbers of revolutions and slight angular errors. If both an angular misalignment and a large angular error are present, the rotational play within this angle would be sufficiently large to prevent the use of the solution from a technical standpoint.
More recently, flexible bolt couplings with rubber elements have been developed. They permit a certain adaptation to varying length and to potential bending angles. But rubber elements of this type prevent the transmission of high torques by the coupling. Here again, there are phase shifts between the drive member and the driven member. In addition to these relative movements, rotational vibrations may also be developed in such a system.